parenthesis

parenthesis — noun

1. one of the two curved punctuation marks ( ), used in pairs to enclose extra info

1.nounB2
Definition

one of the two curved punctuation marks ( ), used in pairs to enclose extra information, page numbers, or a section inside a maths problem; the British English term is 'round bracket'.

Example

Carlos wrote his phone number in parentheses next to his name on the form.

in parentheses (the marks)

The teacher told the class to solve what is inside the parentheses first.

maths: solve inside parentheses first

Common collocations
  • in parentheses
  • open/close parenthesis
  • left/right parenthesis
Synonyms
  • round brackets

    British English equivalent

  • brackets

    British informal; in American English 'brackets' usually means [ ]

Grammar Patterns

in parentheses

put something in parentheses

Usage Note

Almost always plural ('parentheses') because the marks come in pairs. Singular 'parenthesis' refers to one mark only — usually 'left parenthesis' or 'right parenthesis'. American writers say 'parentheses'; British writers more often say 'round brackets' or just 'brackets'.

Common Mistakes

Write your name in parenthesis.
Write your name in parentheses.
the marks come in pairs, so use the plural.

2. a word, phrase, or short sentence that a writer slips into a longer sentence to

2.nounC1
Definition

a word, phrase, or short sentence that a writer slips into a longer sentence to add explanation or extra detail, usually marked off with commas, dashes, or round brackets so the reader can see it is a side comment.

Example

Maya marked the date of the wedding, May 4th, as a parenthesis between two commas.

set off by paired commas

The editor told Marcus to drop the long parenthesis about his uncle from the opening paragraph.

drop / cut a parenthesis

Common collocations
  • a long/short parenthesis
  • add a parenthesis
  • drop a parenthesis
Synonyms
  • aside

    more conversational; often spoken, not written

  • interjection

    shorter and more emotional; not always grammatical

  • insertion

    neutral; emphasises the act of adding text

Grammar Patterns

a parenthesis (in/within something)

Usage Note

Refers to the inserted text itself, not the brackets around it. Distinguish from sense 1 ('round brackets'): a parenthesis in this sense can be set off by commas or dashes, with no brackets at all.

Common Mistakes

She put a parenthesis around the word.
She put parentheses around the word.
the marks themselves are sense 1 and almost always plural; this sense (the inserted phrase) is what goes inside the marks.

3. an extra remark or short story that a speaker slips in while talking, briefly st

3.nounC2
Definition

an extra remark or short story that a speaker slips in while talking, briefly stepping away from the main topic before returning to it.

Example

Dr. Tanaka allowed himself a brief parenthesis about his student days before returning to the lecture.

allow oneself a brief parenthesis

The mayor added, in parenthesis, that the new bus rule had quietly changed last spring.

phrase: in parenthesis

Common collocations
  • in parenthesis
  • a brief/short parenthesis
  • make a parenthesis
Synonyms
  • digression

    more common; emphasises moving away from the topic

  • aside

    neutral; often whispered or off the record

  • tangent

    informal; suggests a longer side topic

Antonyms
  • main point

    what the speaker returns to after the parenthesis

Grammar Patterns

in parenthesis

as a parenthesis

Usage Note

Often appears in the fixed phrase 'in parenthesis' meaning 'as a side comment'. Distinguish from sense 2: this sense is usually about spoken digressions in a talk or lecture, not written inserts in a sentence.

Common Mistakes

He spoke in parentheses about his trip.
He spoke, in parenthesis, about his trip.
the fixed phrase keeps the noun singular.

Word family

  • parentheses
    nounB2
  • parenthetical
    adjectiveC2
  • parenthetically
    adverbC2
  • parenthesise
    verbC2

Synonym discussion

Sense: noun/1

In American English, 'parenthesis' (usually plural 'parentheses') is the standard name for the curved marks ( ). The same shape is called a 'round bracket' in British English, where the unmarked word 'bracket' often means the same thing in everyday use. American writers reserve 'bracket' for the square shape [ ], so an American teacher will say 'put it in parentheses' while a British teacher may say 'put it in brackets' and mean exactly the same. 'Parenthesis' is also the more formal and technical word, common in style guides and printing manuals; 'bracket' feels more everyday. For maths class in Taiwan, English textbooks usually follow the American style: 'Solve what is inside the parentheses first.'

parenthesis ↗bracket ↗round bracket

Common collocations

Nouns

  • pair of parentheses
  • left/right parenthesis
  • opening/closing parenthesis

Phrases

  • put something in parentheses
  • open/close a parenthesis
  • as a parenthesis

Prepositions

  • in parenthesis
  • in parentheses
  • within parentheses

Etymology

GreekLate LatinEnglish

Borrowed in the late 1500s from Late Latin 'parenthesis', itself from Greek 'parenthesis', literally 'a putting in beside'. The Greek word combines 'para-' (beside), 'en-' (in) and 'thesis' (a placing). The earliest English use was the grammatical sense — a phrase 'placed beside' the main sentence — and the meaning 'curved mark used to enclose such a phrase' developed from there.